Hibernate correctly configured does not insert into the database

My code does not enter into the Mysql database. It identifies all the database, the tables and the fields, but the insertion is not done.

UserID.java

package br.com.sistec.dao;

import org.hibernate.Session;
import org.hibernate.Transaction;

import br.com.sistec.domain.Usuario;
import br.com.sistec.util.HibernateUtil;

public class UsuarioDAO {


    public void salvar(Usuario usuario){

        Session sessao = HibernateUtil.getSessionFactory().openSession();
        Transaction transacao = null;

        try{

            transacao = sessao.beginTransaction();
            sessao.save(usuario);
            transacao.commit();


        }catch (Exception ex){
            if(transacao != null){

                transacao.rollback();

            }


        }

            finally{

                sessao.close();
            }
        }



    }

HibernateUtil.java

package br.com.sistec.util;

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

public class HibernateUtil {

    private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        try {

            Configuration configuration = new Configuration();
            configuration.configure();

            ServiceRegistry serviceregistry = new StandardServiceRegistryBuilder()
                    .applySettings(configuration.getProperties()).build();

            SessionFactory sessionFactory = configuration
                    .buildSessionFactory(serviceregistry);

            return sessionFactory;

        }

        catch (Throwable ex) {
            // Make sure you log the exception, as it might be swallowed
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

}

User.java

package br.com.sistec.domain;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name ="tbl_usuario")
public class Usuario {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "cpo_usuid")
    private Long codigo;

    @Column(name = "cpo_usuusuario", length = 40, nullable = false)
    private String usuario;

    @Column(name = "cpo_ususenha", length = 10, nullable = false)
    private String senha;

    public Long getCodigo() {
        return codigo;
    }

    public void setCodigo(Long codigo) {
        this.codigo = codigo;
    }

    public String getUsuario() {
        return usuario;
    }

    public void setUsuario(String usuario) {
        this.usuario = usuario;
    }

    public String getSenha() {
        return senha;
    }

    public void setSenha(String senha) {
        this.senha = senha;
    }

UsernameDAest.java

package br.com.sistec.test;

import org.junit.Test;

import br.com.sistec.dao.UsuarioDAO;
import br.com.sistec.domain.Usuario;

public class UsuarioDAOTest {

        @Test
        public void salvar(){

            Usuario u1 = new Usuario();
            u1.setUsuario("Teste");


            Usuario u2 = new Usuario();
            u2.setUsuario("Teste");


            UsuarioDAO usuDao = new UsuarioDAO();

            usuDao.salvar(u1);
            usuDao.salvar(u2);


    }


}

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/db_sistec</property>
        <property name="connection.username">root</property>
        <property name="connection.password">fatec</property>

        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>

        <!-- Enable Hibernate's automatic session context management -->
        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache -->
        <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

        <!-- Drop and re-create the database schema on startup -->
        <property name="hbm2ddl.auto">validate</property>


        <mapping class="br.com.sistec.domain.Usuario"/>


    </session-factory>

</hibernate-configuration>

Does anyone help me?